The Baltimore City Council on Monday gave preliminary approval to a bill requiring licensing and inspections of all private rental housing in the city, a measure that officials have called “the most significant update” to regulations written half a century ago.

The bill, introduced by Councilman Bill Henry and housing officials, would expand oversight starting next year to include one- and two-unit rental properties — not just larger buildings with three or more units governed by current law.

Those smaller properties generate the most complaints, but have been exempted from mandatory inspections, city officials say.

“We got a lot of good input from advocates from all sides and it made the bill stronger,” Henry said after the council vote.

The legislation was approved 14-1, with Councilman Isaac “Yitzy” Schleifer casting the lone “no” vote. He said he objected to an exemption in the bill that the inspections do not apply to the residents of public housing properties operated by the Housing Authority of Baltimore City.

The council needs to vote on the measure one more time before it advances to the desk of Mayor Catherine Pugh.

“I believe this bill does address some important things,” Schleifer said. “HABC and public housing is excluded. The intention is to improve the quality of housing. I don’t think people in public housing should be excluded.”

The legislation would establish three tiers of licenses, similar to a policy in Minneapolis recently featured by the Baltimore Sun. Compliant landlords who fix violations promptly and avoid the most serious problems would earn a license that requires an inspection only once every three years.

Problematic property owners with more code violations would receive licenses that require inspections annually or every two years.